(English) If you’re starting a new project, you should write it in Kotlin

It’s great to be in our backyard again for Google I/O to connect with Android’s developers around the world. The 7,200 attendees at Shoreline Amphitheatre, millions of viewers on the livestream, and thousand of developers at local I/O Extended events across 80+ countries heard about our efforts to make the lives of developers easier. Today at Google I/O, we talked about two big themes; helping our developers become more productive and strengthening user privacy and security in the platform. Let’s take a closer look at the major developer news at I/O so far:

Developer Productivity

This year, we focused on a simple idea — we want to save you time every today. By making everything you use even better.

Kotlin

Two years ago, we announced Kotlin was a supported language for Android. Our top developers loved it already, and since then, it’s amazing how fast it’s grown. Over 50% of professional Android developers now use Kotlin, it’s been one of the most-loved languages two years running on Stack Overflow, and one of the fastest-growing on GitHub in number of contributors.

Today we’re announcing another big step: Android development will become increasingly Kotlin-first. Many new Jetpack APIs and features will be offered first in Kotlin. If you’re starting a new project, you should write it in Kotlin; code written in Kotlin often mean much less code for you–less code to type, test, and maintain. And we’re continuing to invest in tooling, docs, trainings and events to make Kotlin even easier to learn and use. This includes Kotlin/Everywhere, a new, global series of events that we are launching with JetBrains where you can learn more about the language, new Udacity courses, and more.

Android Jetpack

Last year, we announced Android Jetpack, Android’s API to accelerate Android development and make writing high-quality apps easy, with less code. Over 80% of our top 1000 apps are already using Jetpack, as we continue to simplify more every-day developer challenges. Today, we are releasing 6 new Jetpack libraries (in alpha), and bringing 5 libraries to beta quality. Here are 3 highlights:

CameraX — You’ve told us working effectively across the range of unique Android devices was tough. CameraX is a new open-source Android Jetpack library to make camera development easier and faster. It provides a consistent camera experience across devices, so you no longer have to maintain device specific configurations. You’ll find support for leading-edge hardware and software features like optical zoom, bokeh, HDR, and night mode on participating manufacturer devices. It works with almost 90% of devices (backwards compatible to L). There’s also an easy migration path from legacy Camera APIs and it works seamlessly with camera2 APIs. 70% of camera usage on Android comes from installed apps (not the device camera app) so we’re really excited to make camera development easier.

Architecture Components — We’ve made a number of additions and enhancements based on your feedback. You’ve told us concurrency on Android was hard. So we’re bringing you LiveData and Lifecycles w/ coroutines to support common one-shot asynchronous operations. With the ViewModel with SavedState module, you can eliminate boilerplate code and gain the benefits of using both ViewModel and SavedState with simple APIs to save and retrieve data right from your ViewModel. And in case you missed it, we announced stable releases of WorkManager (background processing) and Navigation (navigation between app screens) just a couple of months ago.

Jetpack Compose — Many of you have been asking us for a modern, reactive style UI toolkit for Android, which takes advantage of Kotlin and integrates seamlessly with the platform and all of your existing code. Today, we’re sharing the team’s work on Jetpack Compose. Jetpack Compose is designed to simplify UI development by combining a reactive programming model with the conciseness and ease-of-use of Kotlin. It’s compatible with the existing UI toolkit, so you can mix and match views with direct access to all of the Android and Jetpack APIs. It’s also fully declarative for defining UI components. And, it’s designed with Material, animations, and tools in mind from the start. Starting today we’re developing this in the open, and you can find all the code on AOSP.

Android Studio

Today we’re releasing Android Studio 3.5 to Beta. For months, the team has been exclusively focused on refining and polishing day-to-day development workflows, with Project Marble. Android Studio 3.5 includes better IDE memory management for large projects, lower typing latency, lint improvements, CPU usage optimizations, layout editor improvements, emulator improvements, build changes, as well as a complete rewrite of Instant Run, now called Apply Changes, that now reliably accelerates the ability to see your code changes on a device — plus over 400 high- priority bug fixes.

Machine Learning at Android scale

In Android Q, we’ve made significant improvements to Android’s Neural Networks API (NNAPI). First, we have increased the number of Operators supported from 38 to over 90. The vast majority of models can now be accelerated by NNAPI with no alterations. We’ve also introduced an introspection API for advanced users, allowing full control over which hardware components handle acceleration (e.g. DSP vs. NPU). And, we’ve worked closely with hardware vendors to deliver significant improvements in performance, both in latency and power consumption. Working with MediaTek, we were able to accelerate ML Kit’s face detection API by 9X on the Helio P90. Working with Qualcomm, we were able to accelerate Google’s Lens OCR on the Snapdragon 855’s AI Engine, increasing speed by 3X while also reducing power consumption by 3.7X.

Dynamic features and in-app updates

Last year we introduced the Android App Bundle to help you reduce app size and increase installs. Since then, we’ve seen over 80,000 app bundles in production, with average size savings of 20%. And today we have a number of announcements to help you reduce size and deliver updates to your users even faster. Today we’re glad to share that dynamic feature modules are moving from beta to stable. With dynamic feature modules, you can reduce your app size even more by choosing which parts of your app to deliver — based on conditions like device features, country. You can even deliver modules on-demand, instead of at install time. And today we’re also moving in-app updates from beta to stable. The ability to dynamically update apps is something you’ve been requesting for a long time. Let’s say you have a crucial bug in your app, and you need to push it out right away; you don’t want to wait until users discover an update in the Play Store. Now you can.

User privacy and security in Android Q

As a developer community, we all care about getting this right. It’s about building a platform that offers powerful capabilities for developers, while making sure that user safety and privacy is protected. We introduced Android Q Beta a few months ago with over 50 features and improvements around user privacy and security. These Q changes provide users more transparency and control.
As always, we are working hard to do everything we can for developers adopting the new release. We know you have your own features to build. That’s why, with these Q changes, we’ve worked very hard to minimize the impact for you, as well as to incorporate your feedback. We’ve given as long a notice period as possible, as well as complete and detailed technical information up front, to make it as easy as possible to adopt. We also want to thank the community for your ongoing feedback. It’s been a huge help to the team who are working hard to get this right. A great example are the Beta 3 storage changes, where your feedback helped us evolve the feature over the course of the Betas. Android has a longstanding commitment to minimizing all breaking changes. Our commitment is unchanged, and we’ll work hard to keep Android the open, flexible, and developer friendly platform we all love.

Be a part of Google I/O!

We’ve got a lot of great content in store for you over the next three days, including over 45 sessions across Android. We’re excited for you to join us in-person here at Shoreline, at an I/O Extended event, or online through the livestream. We’re constantly investing in our platform that connects developers to billions of users around the world. To the entire Android community, thank you for your continued support and feedback, and for being a part of Android.